Do you have multiple internal and external hard drives connected to your PC? If you do, this info might be very important for you, as it allows to save energy, prolong HDD and PC Power Supply Unit (PSU) service life, and avoid BSODs at PC wakeup from sleep or hibernation.

Western Digital and some other HDD makers have been offering for some time Power-up in standby (PUIS) feature in their Hard Drive product lines. This is considered Enterprise RAID product class feature, nonetheless very useful in Workstations and Desktops, including older PCs with multiple drives and weaker PSUs. It requires BIOS support. When activated, it allows to waken up non-system HDDs intoStandby (non-spin) mode at PC wakeup from Standby or Hibernation. Meaning, they won't start spinning at PC wakeup right away, but instead will wait until you try to open a file saved on that HDD or save a file onto it. Otherwise the HDD will follow usual power management cycle during PC operation, meaning it will stop spinning when not accessed for a set time period.

This is a great power saving feature, it prolongs HDD and PSU service life, and allows to avoid voltage & current spikes and drops at simultaneous multiple drive spin-ups, leading to PC wakeup delays and BSODs resulted from delayed access to a system HDD, and causing faster PSU wearing. The feature is described in more details in Working Draft ATA/ATAPI Command Set - 2 (ACS-2):

"The PUIS feature set allows devices to be powered-up into the Standby power management state to minimizeinrush current at power-up and to allow the host to sequence the spin-up of devices . This optional feature setmay be enabled or disabled via the SET FEATURES command; may be enabled by use of a jumper or similarmeans, or both . When enabled by a jumper, this feature set shall not be disabled via the SET FEATUREScommand . The IDENTIFY DEVICE data or IDENTIFY PACKET DEVICE data indicates whether this feature setis implemented and/or enabled.

Once this feature is enabled in a device, the device shall not disable the feature as a result of processing a powercycle, a hardware reset, or a software reset.A device may implement a SET FEATURES subcommand (see 7.50.8) that notifies the device to spin-up to theActive state when the device has powered-up into Standby . If the device implements this SET FEATURESsubcommand and power-up into Standby is enabled, the device shall remain in Standby until the SETFEATURES subcommand is received . If the device implements this SET FEATURES subcommand, the factthat the feature is implemented is reported in the IDENTIFY DEVICE data or IDENTIFY PACKET DEVICE data.If the device:a) implements the Enable/disable Power-up in Standby subcommand;c) has the PUIS feature set enabled; andd) receives an IDENTIFY DEVICE command or IDENTIFY PACKET DEVICE command while the device isin the Standby power mode as a result of powering up in that mode,then the device shall respond to the IDENTIFY DEVICE command or IDENTIFY PACKET DEVICE commandwithout spinning up the media . If the device is unable to return a complete response without accessing themedia, then the device shall set IDENITFY DEVICE data word 0 bit 2 to one to indicate that the response isincomplete . At a minimum, IDENITFY DEVICE data word 0 and IDENITFY DEVICE data word 2 shall becorrectly reported . Those fields that are not provided shall be filled with zeros . Once a device is able to returnall data for an IDENTIFY DEVICE command or IDENTIFY PACKET DEVICE command, the device shall returnall data for those commands until after processing the next power cycle.If the device does not implement the SET FEATURES subcommand to spin-up the device after power-up andPUIS is enabled, the device shall spin-up upon receipt of the first command that requires the device to accessthe media, except the IDENTIFY DEVICE command or the IDENTIFY PACKET DEVICE command."

PUIS can be set (activated) by setting a jumper on each HDD or using a special software tool, if PUIS is supported by your MoBo BIOS and firmware & hardware of your drive models - check your HDD specs to find it out (if not listed in the spec, you may try anyway). Western Digital offers WD SATA and EIDE Hard Drives Jumper Settings Guide for their models. One of reliable tools to activate PUIS by standard commands is offered by Hitachi, and can also be safely used for other HDD makes like Seagate HDDs: Hitachi Feature Tool. There are other tools found on the web capable to activate PUIS.

I wonder if someone used this feature or any brand make tools or jumpers for PUIS activation, and can share your experience, what 3.5' or 2.5' HDD models you found supporting this feature, what tools used to activate it, and any problems faced.

I'd still suggest to try Hitachi Feature Tool first, as it uses strictly standard way to set this feature, thus might be safer for broader choice of HDD models. Once set, this feature can then be removed using the same method that was used to set it. Just don't set it by a jumper, and then remove by a Tool (or wise-versa) to stay out of trouble .

Hello,Sorry for posting here but i didn't find any threads similar with my problem.I have a samsung laptop which i bought recently and the Hitachi HTS547550A9E384 hard drive is making a "clicking" noise whenever it goes idle (when it is parking the actuator's heads). This can happens quite often especially when i only use laptop for reading or surfing simple web pages, and it gets irritating.

I first tried using the Hitachi's Feature Tools but i couldn't make changes to the Advanced Power Management, it said i cannot do the change from there.So i tried a couple of other tools to set the APM value more than the default 128 (which is the state when hdd is clicking frequently).I got it to work using quietHDD, but this program has to be started on every Windows startup. So i went further and used HDAT2 and changed the value to 254 (disabled).

The problem is , after shutdown or sleep/hybernate, the APM is reseted to its initial value, and thus making clicking noise again.

So i want to know how to make the changes be permanent . Btw i also set the Reverting to power-on defaults to disabled , from ATA Commands but with no succes.